由於中國文化以及語言在亞洲，尤其是東亞地區的廣泛影響，耶穌會士進入中國之前，就不得不面對這一挑戰，並對漢字漢語認真研究。因此，我們可以在沙勿略(Xavier,Santa Francisco)、努內斯(Mechior Nunes Barreto)、加戈(Gago Balthazar)等人的信件中看到他們對於中國語言文字的考察，並在孟三德(Eduardus de Sande)、埃斯卡蘭特(Eescalante,Bernardino de)、阿科斯塔(Jose[Joseph] de Acosta)以及陸若漢的著作中找到日臻嚴密的系統研究，這些在中國境外的文化體驗和觀察研究具有特殊的意義。它不僅為利瑪竇(RICCI,Matteo)等入華耶穌會士的傳教活動提供了借鑑作用，而且亦是其文化與語言研究的重要前提與補充。Because of the widespread influence of Chinese culture and its language in Asia, especially in Southeast Asia, the Jesuits had to encounter this challenge before entering China, and they had to study the Chinese Language diligently. Therefore, we have found the evidence of language study in the correspondence of Santa Francisco Xavier, Melchior Nunes Barreto and Balthazar Gago, and we also have found the systematic study of the Chinese language, which was gradually becoming more and more exact and proficient, in the works of Eduardus de Sande, Bernardino de Eescalante, Jose (Joseph) de Acosta and Joao Tcuzu Rodrigues. These cultural experiences and research done by non-Chinese people have a special meaningot only setting an example for the missionary work of the later Jesuits such as Matteo Ricci in China, but also comprising an important premise and complement to the cultural and language research of Matteo Ricci and others.